AP Physics 1 · Unit 2, Part 1 · Forces

Newton’s First Law Practice Problems

Explain inertia and solve balanced-force problems. Compare rest with constant velocity, then calculate supporting forces and tensions for shelves, cables, towing, and angled pulls.

11 questions5 conceptual · 6 calculation

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Simulation scene from the Newton’s First Law lesson. — A scene from the related lesson. Open the practice to work through the questions.

What you’ll practice

Explain equilibrium at rest and in motion

Recognize balanced forces

Use zero acceleration to identify a zero net force. Explain why an object can keep moving after its original push ends.

Resolve forces along two axes

Balance horizontal and vertical components for steady towing and angled pulls. Account for how an upward pull changes the normal force.

Calculate support and tension

Find normal forces and cable tensions for resting and steadily moving objects, including a suspended display held by two unequal cable angles.

A question from this set

Forces on a resting parcel

A parcel rests on a level shelf. Its acceleration is zero. What can you conclude about the forces acting on the parcel?

There are no forces acting on it.
Forces can act, but their vector sum is zero.
The downward force must be larger because gravity acts.

Try it in the practice set

A resting parcel is supported by a level shelf.

Key ideas

Constant velocity is a force-balance condition

Zero net force permits steady motion

Balanced external forces mean zero acceleration. An object can remain at rest or continue at constant velocity, depending on its initial motion.

Balance each direction separately

For equilibrium, horizontal components sum to zero and vertical components sum to zero. Two angled tensions can support a weight even though neither tension equals that weight by itself.

See the physics

Compare balanced forces with steady motion

After checking your answer, watch a resting parcel or a steadily moving object. Compare force directions and reveal numerical values to check the normal force or tension you calculated.

Use a hint for a starting point or open a worked solution to follow the reasoning. Your progress saves in this browser, so you can return to unfinished questions.

Ready for newton’s first law?

Begin with a conceptual question, then work through the calculations.

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